1. Field of the Invention
The present invention relates to an apparatus for therapeutically treating injuries using ultrasound. More particularly, the present invention relates to an apparatus which utilizes a portable signal generator and transducer for treating bone injuries or a variety of musculoskeletal injuries and/or problems.
2. Description of the Related Art
The use of ultrasound to therapeutically treat and evaluate bone injuries is known. Impinging ultrasonic pulses having appropriate parameters, e.g., frequency, pulse repetition, and amplitude, for suitable periods of time and at a proper external location adjacent to a bone injury has been determined to accelerate the natural healing of, for example, bone breaks and fractures. For patients with reduced healing capacity, such as elderly persons with osteoporosis, ultrasonic therapy may promote healing of bone injuries that would otherwise require prosthetic replacement or leave the patient permanently disabled.
U.S. Pat. No. 4,530,360 to Duarte ("Duarte") describes a basic therapeutic technique and apparatus for applying ultrasonic pulses from an ultrasonic applicator placed on the skin at a location adjacent a bone injury. Duarte gives a range of R-F signals for creating the ultrasound, ultrasound power density levels, a range of duration for each ultrasonic pulse, and a range of ultrasonic pulse frequencies. The length of daily treatment is also described. The applicator described in the '360 patent has a plastic tube which serves as a grip for the operator, an R-F plug attached to the plastic tube for connection to an R-F source, and internal cabling connected to an ultrasonic transducer. To apply the ultrasound pulses during treatment an operator must manually hold the applicator in place until the treatment is complete. As a result, the patient is, in effect, immobilized during treatment. The longer the treatment period, the more the patient is inconvenienced.
In general, an ultrasound carrier frequency between 250 kHz and 10 MHz coupled with a relatively low-frequency modulating signal (e.g. 5 Hz to 10 kHz) and low intensity acoustic signal (e.g. less than 100 milliwatts/cm.sup.2) aids, and will be effective in the wound-healing method and apparatus described above.
U.S. Pat. Nos. 5,003,965 and 5,186,162 both to Talish and Lifshey ("Talish '965" and "Talish '162", respectively) describe an ultrasonic delivery system where the R-F generator and transducer are both part of a modular applicator unit that is placed at the skin location. The signals controlling the duration of ultrasonic pulses and the pulse repetition frequency are generated apart from the applicator unit. Talish '965 and Talish '162 also describe fixture apparatus for attaching the applicator unit so that the operative surface is adjacent the skin location. In Talish '965 and Talish '162, the skin is surrounded by a cast, while in U.S. Pat. No. 5,211,160 to Talish and Lifshey ("Talish '160") fixture apparatus is described for mounting on uncovered body parts (i.e.,, without a cast or other medical wrapping). Talish '160 also describes various improvements to the applicator unit.
Duarte, Talish '965, Talish '162, and Talish '160, are all incorporated into this application by reference.
While the systems described in these patents relate to therapeutic methods and apparatus for ultrasonically treating injured bone, they do not disclose a self-contained signal. generator and transducer which permits maximum patient mobility during treatment. Therefore, a need exists for apparatus which optimizes patient mobility during therapeutic ultrasonic treatment.